The objectives of this research are to further our understanding of the molecular basis for the cyclic nucleotide regulated metabolic functions in the body. The enzymology of cyclic nucleotide binding proteins, particularly their isolation and characteristics, will be stressed. Of particular importance will be the examination of isozymes for cyclic AMP and cyclid GMP dependent protein kinases and phosphodiesterases. Both classical and newly developed fractionation procedures will be utilized and immunocytochemical localization experiments will be carried out, utilizing specific antibodies to the purified component proteins. Finally, the kinetic interactions of the purified components will be studied.